About one-quarter of metropolitan Sydney residents will be affected by more than 90 sweeping changes to state laws that were passed by Parliament last year.

Apartment owner Paul Bacon is particularly worried about recently released draft regulations to accompany the changes, to be finalised before the law comes into force in November, including the controversial proposal to allow a building to be sold if 75 per cent of owners approve. Currently all owners must approve any sale.

Investors own about half the units in his Belmore building, and he worries a critical mass may easily be persuaded to sell to developers aiming to build 11,000 new dwellings in the area in the next 20 years.

"I saved for years and years to buy a place for my elderly years," he said. "The investor-owners have somewhere else to go but I don't. I had no idea this could happen."

"It's an attack on low-income families and the disadvantaged and the end of title ownership as we know it".

Fair Trading Minister Victor Dominello says power to ensure such sales run fairly lies with the Land and Environment Court, a superior court that oversees the sales and must ensure they meet six fairness tests.

The government says the court must be satisfied developers  do not unduly influence any sale, that proceeds are equally shared and, in a broadly worded legislative provision, sales are "just and equitable in all the circumstances".

"I can't think of a more definitive protection," Mr Dominello said. "There is no chance vulnerable people will be forced into worse situations with the court given the power to look at all the circumstances".

But the state opposition argues the vulnerable are not protected in the draft regulations. 

"There is no overriding public interest test," said Yasmin Catley, Labor's spokeswoman for regulation and innovation. "It favours property developers over the long-established rights of ordinary homeowners."

But the government says vulnerable tenants such as the elderly will not be forced out or exploited by majority-triggered sales.

The NSW reforms aim to address the issue of the city's ageing housing stock. Other states have staggered thresholds for majority-triggered sales that decrease with the age of the building.

In a note to clients on Friday, Andrew Chew and Han Yong, lawyers from Sydney commercial firm Corrs Chambers Westgarth, have argued that proposed new regulation of building defects "will give [strata] owners greater protection" and aim to avert protracted legal disputes with property developers.

Under proposed regulations, developers will need to make a 2 per cent deposit for surety against any building faults.

There are about 75,000 strata schemes in NSW, according to government estimates. They govern properties to the value of $350 billion.